Katie Venne does homework as her mother Sylvie works on dinner in the kitchen. / H. Darr Beiser, USA TODAY

by Greg Toppo, USATODAY

by Greg Toppo, USATODAY

Parental concerns about ever-expanding homework assignments for their children may be misguided, according to new research suggesting that students' homework burdens have barely changed in 30 years.

The share of 17-year-olds who said they had one to two hours of homework on a typical night dropped from 27% in 1984 to 23% in 2012, according to a report today in the annual Brown Center Report on American Education, sponsored by the Brookings Institution, a liberal think tank based in Washington, D.C. The percentage who spent more than two hours a night on homework remained unchanged at 13%.

In a separate survey by researchers at the University of California-Los Angeles, the percentage of college freshmen nationwide who recalled having six or more hours of homework a week during their senior year in high school dropped from 50% in 1986 to 38% in 2012.

"It still doesn't look like kids are overworked," says researcher Tom Loveless, a longtime education researcher and former public school math teacher who conducted the Brookings study. "The percentage who are overworked is really small."

The findings come amid complaints by some parents that their children's homework load is out of control. In one recent survey, 46% of parents in Bernards Township, N.J., said their children spend too much time on homework. Only 4.6% said their kids don't have enough homework.

Some school districtsare considering explicit time limits on nightly homework assignments, and a few are even talking about making homework optional.

Loveless analyzed several previous surveys, including data from the federally administered National Assessment of Educational Progress (NAEP), a set of basic-skills tests given periodically to 9-, 13- and 17-year-olds. Among survey questions included in NAEP: "How much time did you spend on homework yesterday?"

More 17-year-olds reported having no homework at all. From 1984 to 2012, the percentage who said they had "none assigned" grew from 22% to 27%. Another 11% said they had homework but didn't do it, a figure unchanged over 28 years.

The only significant increase in homework, the NAEP study found, was for 9-year-olds. In 1984, 35% reported no homework the previous night. By 2012, that had shrunk to 22%. The share of students reporting less than an hour of homework rose from 41% to 57%. The percentage of 9-year-olds with an hour or more of homework shrank by two percentage points, from 19% to 17%.

Loveless says previous research has suggested that parents who complain about homework are often already "alienated from the school" for other reasons.

Mike Petrilli of the Thomas B. Fordham Institute, an education think tank, says the homework picture looks very different for different groups of students. College-bound students pushing for admittance to elite universities "probably are doing too much homework and are stressed out about it." But the rest of the USA's student population, he says, "are not being pushed to do a lot of homework at all."